Tunneling Begins on Scarborough Subway Extension

Tunneling is officially underway on Scarborough’s 7.8-km subway extension, Metrolinx reported on Jan. 18. The much-needed extension will bring subway service farther north into Scarborough and accommodate as many as 105,000 daily boardings.

Since the TBM arrived from Germany late last year, crews at the project’s launch shaft, located at Sheppard Avenue East and McCowan Road, have been busy preparing the excavation required to bring the tunnel boring machine (TBM) to life.

Over the next couple years, the TBM will travel 10 to 15 m a day, making its way south from the launch shaft site toward Eglinton Avenue East and Midland Avenue. It will dig about 6.9 km of the 7.8-km tunnel that will be required to bring seamless subway service farther into Scarborough.

The remaining portion of the tunnel will be built by the contractor for the stations, rail and systems contract. At 10.7 m wide, this will be the first subway tunnel in Toronto to contain two subway tracks operating in both directions.

As tunneling gets underway, crews have already started work at the project’s extraction shaft site at Midland Avenue and Eglinton Avenue East, where the TBM will be extracted from the ground after completing its journey.

For the latest information on the Scarborough Subway Extension, visit the project website.

By Joshua Patel, Metrolinx communications senior advisor, subway program.